[mod] ADS engine: revision of the engine (Paper result)

Revision of the Astrophysics Data System (ADS) engine / use of the result type
Paper as well as other typifications.

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

searx/settings.yml

@@ -407,13 +407,12 @@ engines:
       require_api_key: false
       results: JSON
 
-  # - name: astrophysics data system
-  #   engine: astrophysics_data_system
-  #   sort: asc
-  #   weight: 5
-  #   categories: [science]
-  #   api_key: your-new-key
-  #   shortcut: ads
+  - name: astrophysics data system
+    engine: astrophysics_data_system
+    shortcut: ads
+    # read https://docs.searxng.org/dev/engines/online/astrophysics_data_system.html
+    api_key: ""
+    inactive: true
 
   - name: alpine linux packages
     engine: alpinelinux